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Home • About Us • Laboratory Services • Forensic Science Communications • Back Issues • October 2005 • Research • Table 5 - Improvements to the Test Procedure Made...

Table 5 - Improvements to the Test Procedure Made for Trial 2

Table 5: Improvements to the Test Procedure Made for Trial 2

Step

Modification to Test Procedure
(See Table 2.)

Comment

6b

Overlay comparison of waveforms made at optimum replay-tracking setting, as well as at manually set left, center, and right replay-tracking positions.

Differences in radio-frequency waveform are more evident when viewed using different replay-tracking settings.

6c

The examples in Figure 7 may help to determine what is a minor or a noticeable difference and at what point the difference is unclear.

In Trial 1, the waveforms (a) and (c) in Figure 7 were incorrectly matched.

6d

Critically compare overlaid waveforms at various points along the tape to increase awareness of the range of variations.

The shape of the radio-frequency pattern may fluctuate at various points in the recording.